ST fiber-optic line bus RS485 interface
ST fiber-optic line bus RS485 interface
WT65210
Connect RS422 or RS485 devices using glass fiber optic cable
1.635,00 kr. (ex. VAT)
ST fiber-optic line bus <> RS485 interface
Network bus systems over glass fiber optics
Using multiple glass fiber optic adapters model 65210 a copper-based RS485 master-slave bus can be converted into an optical bus without additional protocols. Transmission is at a rate of up to 1.5 Mbaud and in any data format.

Application: Bus system for RS485 devices on fiber-optic base
Background information: For data transmission across long distances and/or in extremely interfering environments, we strongly recommend the use of fiber-optic cables. Easily installed connections over relatively short distances up to 100 m are made possible by the use of plastic optical fiber cables, whereas for a distance segment of up to 3800 m, the use of fiber-optic lines is made necessary. The attenuation of the light in fiber-optic lines is considerably lower than that in plastic optical fiber cables.
While, in the past, the installation and preparation of fiber-optic lines was rather difficult, many suppliers now offer a comprehensive service of installation and customizing of cables, due to the fact that fiber-optic technology is now increasingly applied in commercial networks.
Product properties:
Interfaces:
- 1 x RS485
- 9-pin Sub-D plug
- 2- and 4-wire operation
- 2 x Multi-mode glass fiber optics
- ST connector
Management and connectivity:
- No re-configuration of transmission parameters required
- Transmission of two data channels
- Noise-immune transmission over a distance of up to 3800 meters per segment
- Galvanic isolation up to nearly any value between the connected devices
Power supply:
- External
- 12V-24V AC/DC via plug-in screw terminal
- Galvanically isolated power connection
Standards & more
- Conforms to standards both in office and industrial environments:
- High noise resistance per EN 61000-6-2
- Low noise emission per EN 55032:2015 + A1 Cl. B, EN 61000-3-2 & EN 61000-3-3
- 5 year guarantee
Connections and displays:
- Serial port:
- RS485 interface
- 9-pin SUB-D adapter
- Glass fiber optics port:
- ST plug adapter
- SMA plug adapter on request
- Operating modes:
- 4-wire with automatic control
- 2-wire with automatic control
- Switching time:
- approx. 10µs for changing from data sending to receiving for RS485 automatic control (can be modified on request)
- Baud rate:
- 0..1.5Mbaud
- Data format:
- any format
- Supported topologies:
- Bus and star, but no ring structures
- Supported signals:
- RxD, TxD
- Cascadability:
- 5 adapters @115Kbaud, 32 adapters @19.2Kbaud
- Fiber-optic medium:
- Multi-mode fiber 50/125μm, 62.5/125μm
- Wavelength:
- 820nm
- Optical budget:
- 50/125µm: typically 9.6dB, min. 4.2dB
- 62.5/125µm: typically 13.4dB, min. 8.0dB
- Maximum distance:
- 50/125µm: typically 3200m, min. 1400m @3dB/km
- 62.5/125µm: typically 3800m, min. 2200m @3.5dB/km
- Galvanic isolation:
- Isolation voltage min. 1 KV DC between power and the serial port
- Supply voltage:
- 12..24V AC/DC
- Current consumption:
- typ. 80mA @12V DC, 40mA @24V DC
- Supply connection:
- Plug-in screw terminal, 5.08mm spacing
- Labeled "L+" and "M"
- Displays:
- 1x LED Data
- 1x LED Power
Housing and other data:
- Housing:
- Plastic housing for top hat rail installation
- 105 x 45 x 75mm (L x W x H)
- Enclosure rating:
- IP20
- Weight:
- approx. 100g
- Ambient temperature:
- Storage: -40..+70°C
- Operating in non-rowed installation: 0..+60°C
- Operating in rowed installation 0..+50°C
- Permissible relative humidity:
- 5..95% RH (non-condensing)
- Life expectancy:
- > 25 years at 25°C ambient temperature
- Scope of delivery:
- ST fiber-optic line bus <> RS485 interface
- Please order power supplies separately as accessories

